N=int(input())
Mod=10**9+7

DP=[["*",0,0,0] for _ in range(N+4)]
DP[1]=["*",1,0,0]
DP[2]=["*",0,1,0]
DP[3]=["*",0,0,1]

for i in range(1,N+1):
    for s in [1,2,3]:
        for t in [1,2,3]:
            if s!=t:
                DP[i+s][s]+=DP[i][t]
                DP[i+s][s]%=Mod

print(sum(DP[N][1:])%Mod)